Stepped Spillway Hydraulic Characteristics

The desire for the new energy dissipator become more and more stronger with the modern hydraulic engineering developing continuously which urge for a large number of new energy dissipators represented by the stepped energy dissipator. The appearance of the stepped energy dissipator solves a lot of practical problems indeed in the engineering including the poor effect of energy dissipation, the complexity of the energy dissipation structure, high cost of works, the poor effect of landscape design, the poor effect of preventing river sand and the poor fish road project because of the significant effect of energy dissipation and the special structure.But until now there are still many hydraulic characteristics which haven't been studied clearly because of the complex boundary conditions of the stepped spillway and the two-phase state of water and vapor.Based on the stepped spillway of the Da-hebian Reservoir model the similarity theory of gravity is applied in this paper. The test results of hydraulics characteristics including the flow pattern, the velocity distribution, the aeration characteristics, the energy dissipation characteristics, the depth of flow and the division of flow structure are obtained by making experiments in five kinds of flow conditions. The test results have important significance to the application of the stepped spillways in the engineering and could provide a scientific basis. The research results of this paper are as following:1. The starting point of aeration of this kind of stepped spillway is studied.2. The flow velocity distribution of this kind of stepped spillway is studied.3. The energy dissipation characteristic of this kind of stepped spillway is studied.4. The limit of the division of flow of this kind of stepped spillways is obtained which is the size relation of the critical depth and the high-level steps.5. The depth distribution of flow of this kind of stepped spillway is studied.